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本文總結(jié)：Java 通過(guò)反射設(shè)置對(duì)象屬性值，或者獲取對(duì)象屬性值，編碼過(guò)程中反射結(jié)合泛型使用可以代碼復(fù)用，減少冗余代碼；
食用建議：配合場(chǎng)景案例食用更佳；
設(shè)置/獲取屬性
實(shí)體類對(duì)象：
@AllArgsConstructor
@NoArgsConstructor
@Data
public class StudentScore {
/**
* 名稱
*/
private String name;
/**
* 科目
*/
private String subject;
/**
* 成績(jī)
*/
private Integer score;
}
方式一
通過(guò)Field操作屬性：
public void method1() throws Exception {
Class<StudentScore> cls = StudentScore.class;
StudentScore obj = new StudentScore();
StudentScore obj2 = new StudentScore();
/*
* 設(shè)置屬性
*/
Field nameField = cls.getDeclaredField("name");
nameField.setAccessible(true);
nameField.set(obj, "張三");
Field subjectField = cls.getDeclaredField("subject");
subjectField.setAccessible(true);
subjectField.set(obj, "語(yǔ)文");
Field scoreField = cls.getDeclaredField("score");
scoreField.setAccessible(true);
scoreField.set(obj, 100);
/*
* 獲取屬性
*/
Field[] fields = cls.getDeclaredFields();
for (Field field : fields) {
String s = Modifier.toString(field.getModifiers());
// 排除final修飾的屬性
if (!s.contains("final")) {
field.setAccessible(true);
// 通過(guò)filed獲取設(shè)置屬性
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", field.getName(), field.get(obj));
// obj對(duì)象屬性值賦值給obj2
field.set(obj2, field.get(obj));
}
}
System.out.println("method1 obj：" + JSONObject.toJSONString(obj));
System.out.println("method1 obj2：" + JSONObject.toJSONString(obj2));
}
運(yùn)行結(jié)果：
方式二
通過(guò)set方法：
public void method2() throws Exception {
Class<StudentScore> cls = StudentScore.class;
StudentScore obj = new StudentScore();
/*
* 設(shè)置屬性
*/
Method setName = cls.getMethod("setName", String.class);
setName.invoke(obj, "李四");
Method setSubject = cls.getMethod("setSubject", String.class);
setSubject.invoke(obj, "語(yǔ)文");
Method setScore = cls.getMethod("setScore", Integer.class);
setScore.invoke(obj, 114);
/*
* 獲取屬性
*/
Method getName = cls.getMethod("getName");
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "name", getName.invoke(obj));
Method getSubject = cls.getMethod("getSubject");
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "subject", getSubject.invoke(obj));
Method getScore = cls.getMethod("getScore");
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "score", getScore.invoke(obj));
System.out.println("method2：" + JSONObject.toJSONString(obj));
}
運(yùn)行結(jié)果：
方式三
通過(guò)屬性名：
public void method3() throws Exception {
Class<StudentScore> cls = StudentScore.class;
StudentScore obj = new StudentScore();
/*
* 設(shè)置屬性
*/
PropertyDescriptor namePd = new PropertyDescriptor("name", cls);
Method writeMethod = namePd.getWriteMethod();
writeMethod.invoke(obj, "王五");
PropertyDescriptor subjectPd = new PropertyDescriptor("subject", cls);
Method subjectMethod = subjectPd.getWriteMethod();
subjectMethod.invoke(obj, "語(yǔ)文");
PropertyDescriptor scorePd = new PropertyDescriptor("score", cls);
Method scoreMethod = scorePd.getWriteMethod();
scoreMethod.invoke(obj, 127);
/*
* 獲取屬性
*/
Method nameRead = namePd.getReadMethod();
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "name", nameRead.invoke(obj));
Method subjectRead = subjectPd.getReadMethod();
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "subject", subjectRead.invoke(obj));
Method scoreRead = scorePd.getReadMethod();
System.out.printf("獲取屬性值，當(dāng)前屬性：%s，值：%s%n", "score", scoreRead.invoke(obj));
System.out.println("method3：" + JSONObject.toJSONString(obj));
}
運(yùn)行結(jié)果：
場(chǎng)景案例
場(chǎng)景：學(xué)生查詢自己的語(yǔ)文考試成績(jī)；
學(xué)生成績(jī)對(duì)象實(shí)體類:
/**
* 學(xué)生成績(jī)實(shí)體
*/
@AllArgsConstructor
@NoArgsConstructor
@Data
public class StudentScore {
/**
* 名稱
*/
private String name;
/**
* 科目
*/
private String subject;
/**
* 成績(jī)
*/
private Integer score;
}
學(xué)生對(duì)象實(shí)體類：
/**
* 學(xué)生-張三
*/
@Data
public class StudentZS extends StudentScore {
}
/**
* 學(xué)生-李四
*
*/
@Data
public class StudentLS extends StudentScore {
}
/**
* 學(xué)生-王五
*/
@Data
public class StudentWW extends StudentScore {
}
測(cè)試：文章來(lái)源：http://www.zghlxwxcb.cn/news/detail-732210.html
@Test
public void testDemo() {
StudentZS student1 = new StudentZS();
student1.setName("張三");
scoreSystem(student1, StudentZS.class);
System.out.println("張三查詢成績(jī)結(jié)果：" + JSONObject.toJSONString(student1));
StudentLS student2 = new StudentLS();
student2.setName("李四");
scoreSystem(student2, StudentLS.class);
System.out.println("李四查詢成績(jī)結(jié)果：" + JSONObject.toJSONString(student2));
StudentWW student3 = new StudentWW();
student3.setName("王五");
scoreSystem(student3, StudentWW.class);
System.out.println("王五查詢成績(jī)結(jié)果：" + JSONObject.toJSONString(student3));
}
/**
* 成績(jī)系統(tǒng)
*
* @param t 學(xué)生
* @param cls 學(xué)生類
* @param <T> 泛型
*/
public <T> void scoreSystem(T t, Class<T> cls) {
// 給傳入對(duì)象賦值名稱
try {
Class<? super T> superclass = cls.getSuperclass();
Field nameField = superclass.getDeclaredField("name");
Type genericType = nameField.getGenericType();
String typeName = genericType.getTypeName();
assert "java.lang.String".equals(typeName);
nameField.setAccessible(true);
String studentName = nameField.get(t).toString();
int schoolReport = 0;
switch (studentName) {
case "張三":
schoolReport = 100;
break;
case "李四":
schoolReport = 114;
break;
case "王五":
schoolReport = 127;
break;
}
Field subjectField = superclass.getDeclaredField("subject");
subjectField.setAccessible(true);
subjectField.set(t, "語(yǔ)文");
Field scoreField = superclass.getDeclaredField("score");
scoreField.setAccessible(true);
scoreField.set(t, schoolReport);
} catch (Exception e) {
e.printStackTrace();
}
}
運(yùn)行結(jié)果：
文章來(lái)源地址http://www.zghlxwxcb.cn/news/detail-732210.html
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